Timing-gear-chain adjuster



April 22 1924. 1,491,716

T. M. McKELVY TIMING GEAR CHAIN ADJUSTER Filed April 10 1922 Patented Apr. 22, 1924. r

' UNITED. STATES THOMAS M. McKELVY, or FRESNO, CALIFORNIA. 3

I TIMING-GEAR-CHAIN ADJUSTER.

Application filed April 10, 1922. Serial 110,551,429.

To all whom it may concern:

Be it known that I, THOMAS M. MoKELvY, a citizen of the United States, residing at Fresno, in the county of Fresno and State of California, have invented certain new and useful Improvements in Timing-Gear- Chain Adjusters; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to new and useful improvements in internal combustion engine timing gear chain adjusters and has for its primary object the provision of a device especially adapted for taking up the slack in the chain employed to drive the rotary intake and exhaust valves of an engine, and which forms the subject matter of my copending application filed September 12th,

1921, and serially numbered 500,029 by applying force or tension to each vertical run of the chain, and which device may be easily and quickly actuated with the minimum expenditure of manual labor and time.

Another object of this invention is the provision of a timing gear chain adjuster of the above stated character which will be simple, durable, and efficient, and which may be manufactured and sold at a comparatively low cost.

With these and other objects in view as will become more apparent as the description proceeds, the invention consists in certain novel features of construction, combination, and arrangement of part as will be hereinafter more fully described and claimed.

vention reference is to be had to the follow-.

ing description and accompanying drawings in which Fig. 1 is a front elevation, illustrating a timing gear chain for operating the intake and exhaust valves of an engine with an adjuster applied thereto and constructed in accordance with my invention, and

Fig. 2 is a sectional view illustrating the mounting of the adjuster.

Referring in detail to the drawing, the numeral 1 indicates an internal combustion engine having applied thereto intake and exhaust rotary valves that form the subject matter of my copending application heretofore referred to, and which have gears 2 and 3 located within the timing gear chamber 4 of the engine ,1 en the chamber is e e d'by a removable cover. 'Also located in the chamber 4: is a gear 5. connected to the cam shaft 6 of the engine 1. The gears 2,- 3, and 5 are connected together by an endless chain 7 whereby the valves heretofore referred. to are driven from the cam shaft of the engine. After the chain 7 has. been in use for a time, the same stretches consequently causes a slack in the chain which if allowed to remain or to increase insize will cause the valves to become out of time and thereby cause improperfunction or operation of the engine and to overcome this objection or to provide a convenient means for taking up the slack in the chain' 7, an adjuster 8 is provided which comprises blocks 9 slidably mounted in transversely extending guides 10 formed in the inner wall of the timing gear chamber and said blocks are provided with shafts 11 on which are j ournaled gears 12 that mesh with the chain 7 at diametrical one of the ends of the shaft are provided with right hand screw threads, while the other boss in the other end of said shaft is provided with left hand screw threads so that the rotation of the shaft in one direction will cause a separation of the blocks consequently applyinga force on the vertical runs of the chain to remove 'or take up the slack within the chain. A rotation of the shaft in an opposite direction decreases the force against the vertical runs of the chain consequently permitting the chain to have a desired slack in the same in case the chain happens to be adjusted too tightly. i

From the foregoing description taken in connection with the accompanyingv drawings, it will be noted that a device has been provided which will take up-the slack in the chain at twoopoints in such a way that the timing of the rotary valves is not altered, and also it is to be noted that this device is completely housed and can be easily actuated by simply removing the cover plate to the timing gear chamber of the engine.

While I have shown and described the preferred embodiment .of my invention, it will be understood that minor changes in construction, combination, and arrangement of parLtsniay be madevvi'thou't departing from "the spirit and'scope of theinvention as claimed.

Having thus descrihedmy nven ion Wha I claim is In combination, anengi'ne having relatively spaced driven timing sprockets and a driving sprocket located below the driven sprockets, a chain passing about all of said sprockets, guides carried'by the engine and located between the driven and sprockets and iii a planein rear of the ver tidal plane oecupied by thesprockets, blocks slidably mounted by said guides, chained? jusfiiri sp o e s ieu e led 111 .9 th

faces of said blocks and engaging the inner sides of the chain, and said "chain" adjusting sprockets being mounted for simultaneous adjustment 'in a plane parallel to the plane passing through the axis of the driven sprockets, whereby any slack occurring in the chain may be taken up Without altering the timed relation between the driven sprockets;

In testimony whereof I afiig: my signature in. r senc e i ii' s s- TH MAS MQKELV \Vitnesses:

' JA K,

FRaNGEsL'IBLAIn. 

